System.Text.RegularExpressions.RegexParser.AssignNameSlots C# (CSharp) Method

        internal void AssignNameSlots()
        {
            if (_capnames != null)
            {
                for (int i = 0; i < _capnamelist.Count; i++)
                {
                    while (IsCaptureSlot(_autocap))
                        _autocap++;
                    string name = _capnamelist[i];
                    int pos = (int)_capnames[name];
                    _capnames[name] = _autocap;
                    NoteCaptureSlot(_autocap, pos);

                    _autocap++;
                }
            }

            // if the caps array has at least one gap, construct the list of used slots

            if (_capcount < _captop)
            {
                _capnumlist = new int[_capcount];
                int i = 0;

                // Manual use of IDictionaryEnumerator instead of foreach to avoid DictionaryEntry box allocations.
                IDictionaryEnumerator de = _caps.GetEnumerator();
                while (de.MoveNext())
                {
                    _capnumlist[i++] = (int)de.Key;
                }

                Array.Sort(_capnumlist, Comparer<int>.Default);
            }

            // merge capsnumlist into capnamelist

            if (_capnames != null || _capnumlist != null)
            {
                List<string> oldcapnamelist;
                int next;
                int k = 0;

                if (_capnames == null)
                {
                    oldcapnamelist = null;
                    _capnames = new Hashtable();
                    _capnamelist = new List<string>();
                    next = -1;
                }
                else
                {
                    oldcapnamelist = _capnamelist;
                    _capnamelist = new List<string>();
                    next = (int)_capnames[oldcapnamelist[0]];
                }

                for (int i = 0; i < _capcount; i++)
                {
                    int j = (_capnumlist == null) ? i : (int)_capnumlist[i];

                    if (next == j)
                    {
                        _capnamelist.Add(oldcapnamelist[k++]);
                        next = (k == oldcapnamelist.Count) ? -1 : (int)_capnames[oldcapnamelist[k]];
                    }
                    else
                    {
                        string str = Convert.ToString(j, _culture);
                        _capnamelist.Add(str);
                        _capnames[str] = j;
                    }
                }
            }
        }